VARNISH HIGH AVAILABILITY 1.2 IS OUT

We are back! Only a few weeks after the release of Varnish High Availability 1.1, we are releasing a new version of VHA a little before the new year, so your 2016 cache setups can be even more efficient and resilient.

Just like a good Star Wars movie, this blog post is better enjoyed if you have seen the previous one. So, if VHA is new to you, please make a detour to read more here. Don’t worry, I’ll wait.

Good?

Let’s go then. Don’t be put off by the short changelog, while this release isn’t the feature-piñata that 1.1 was, it’s all about polish, and making your life (or your ops team’s) easier.

What’s new?

ESI support: if you use dynamic content with Varnish, you are probably familiar with ESI. It allows you to include various objects inside a page on the server-side, letting Varnish build content using cached objects. VHA is now able to replicate this content, including all the multiple sub-requests caused by it, giving you replication without losing granularity in your content.

Better job scheduling: With v1.1 we gained support for multiple neighbors, but it was still a bit wild west-y, and in some circumstances, a slow neighbor could slow the replication for the other, well-behaved servers. This limitation has been fixed, letting the fast guys be fast no matter what.

Better autoscaling integration: VHA used to be very picky about its configuration file. Now it's smarter and allows you to run/reload without neighbors for example. This permits an easier management of elastic clusters, a very popular setup. While not exactly part of VHA, I’d like to point out that we now have a ready-made solution to reconfigure automatically your VHA setup in a elastic cluster context. So if a neighbor is taken down or pops up, we’ll now and act on it.

Strict mode: Tight discipline also has its merits, and in a fixed setup, you may want to keep the old, picky behaviour as an effective error detection mechanism. Well, you can! You only need to activate an option, and you’re set.

Optional node name: VHA is able to use the hostname of the machine as it node name, making the '-m' switch optional, and above all, adding genericity to the configuration.

And of course, we also fixed the rare bugs we found!

Where do I get the new VHA?

If you are already a Varnish Plus customer, the packages are already available in your repositories. If you are not a customer but would like to try VHA, please drop a mail to our sales team so we can arrange a trial or demo with you.

Image (c) Stephen Donaghy 2006 used under a Creative Commons license.